1. Field of the Invention
The present invention generally relates to fabrication of integrated circuits in the semiconductor industry.
2. Discussion of the Background
The fabrication of integrated circuits (IC) in the semiconductor industry typically employs plasma to create and assist surface chemistry within a material processing chamber necessary to remove material from and deposit material to a substrate. In general, plasma is formed within the processing chamber under vacuum conditions by heating electrons to energies sufficient to sustain ionizing collisions with a supplied process gas. Moreover, the heated electrons can have energy sufficient to sustain dissociative collisions and, therefore, a specific set of gases under predetermined conditions (e.g., chamber pressure, gas flow rate) are chosen to produce a population of charged species and chemically reactive species suitable to the particular process being performed within the chamber (e.g., etching processes where materials are removed from the substrate or deposition processes where materials are added to the substrate).
The semiconductor industry is constantly striving to produce smaller ICs and to increase the yield of viable ICs. Accordingly, the material processing equipment used to process the ICs have been required to meet increasingly more stringent performance requirements for etching and deposition processes (e.g., rate, selectivity, critical dimension).